Merge branch '6.4' into 7.2

* 6.4:
  fix tests with Doctrine ORM 3.4+ on PHP < 8.4
  reject URLs with URL-encoded non UTF-8 characters in the host part
  Bump Symfony version to 6.4.21
  Update VERSION for 6.4.20
  Update CONTRIBUTORS for 6.4.20
  Update CHANGELOG for 6.4.20

Author: xabbuh